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Diagnostic performance of 7 rapid IgG/IgM antibody tests and the Euroimmun IgA/IgG ELISA in COVID-19 patients.
Clin Microbiol Infect. 2020 May 28;:
Authors: Van Elslande J, Houben E, Depypere M, Brackenier A, Desmet S, André E, Van Ranst M, Lagrou K, Vermeersch P
Abstract
OBJECTIVES: To evaluate the diagnostic performance of 7 rapid IgG/IgM tests and the Euroimmun IgA/IgG ELISA for antibodies against SARS-CoV-2 in COVID-19 patients.
METHODS: Specificity was evaluated in 103 samples collected before January 2020. Sensitivity and time to seropositivity was evaluated in samples from 94 patients with COVID-19 confirmed with PCR on nasopharyngeal swab.
RESULTS: Specificity [confidence interval] of lateral flow assays (LFA) was ≥ 91.3% [84.0-95.5] for IgM, ≥ 90.3% [82.9-94.8] for IgG, and ≥ 85.4% [77.2-91.1] for the combination IgM OR IgG. Specificity of the ELISA was 96.1% [90.1-98.8] for IgG and only 73.8% [64.5-81.4] for IgA. Sensitivity 14-25 days after onset of symptoms was ≥ 92.1% [78.5-98.0] to 100% [95.7-100] for IgG LFA compared to 89.5% [75.3-96.4] for IgG ELISA. Positivity of IgM OR IgG for LFA resulted in a decrease in specificity compared to IgG alone without a gain in diagnostic performance except for VivaDiag. The results for IgM varied significantly between the LFA with an average overall agreement of only 70% compared to 89% for IgG. The average dynamic trend to seropositivity for IgM was not shorter than for IgG. At time of admission to the hospital, the sensitivity of LFA was <60%.
CONCLUSIONS: Sensitivity for the detection IgG antibodies 14-25 days after onset of symptoms was ≥ 92.1% for all 7 LFA compared to 89.5% for the IgG ELISA. The results for IgM varied significantly and including IgM antibodies in addition to IgG for the interpretation of LFA did not improve the diagnostic performance.
PMID: 32473953 [PubMed - as supplied by publisher]